Proposal of roll angle control method using positive and negative anti-dive force for electric vehicle with four in-wheel motors

Electric vehicles (EVs) have been gaining a lot of attention due to its environmental friendliness. EVs can be controlled precisely with the quick response of the motor. Moreover, using in-wheel motors, several types of motion controls can be performed. Therefore, such motion control of EVs have been intensely researched. This paper focuses on the control of roll angle which occurs during cornering. If this roll angle becomes large, steering response will be deteriorated, and also stability will decrease. Therefore, it is necessary to appropriately control the roll angle. In this paper, roll angle control method using positive and negative anti-dive force for EVs with four in-wheel motors has been proposed. Using positive and negative anti-dive force, the number of necessary actuators such as active suspensions can be reduced. The proposed method is also considering workload control of each wheel based on least square method. By estimating the roll moment disturbance using the roll moment observer, roll angle control has become a robust control system against disturbances. Thus, the proposed method allows improvement of vehicle´s stability, safety and riding comfort during cornering. The effectiveness of the proposed method is verified by simulation and experimental results. Results of the roll angle control system without workload consideration and results of the case with workload consideration are also compared.